Vehicle occupant detection systems are useful in determining a position and a classification of an occupant of a vehicle. Actuation of an air bag assembly may be controlled in response to the determined position and classification of the occupant.
A significant challenge to using an image system for determining the position and the classification of an occupant of a vehicle is differentiating the occupant from the background objects of the vehicle. If the background objects of the vehicle are confused with the occupant, the potential for incorrectly determining the position and the classification of the occupant increases significantly.
U.S. Pat. No. 5,531,472 includes a system for determining the location of an occupant of a vehicle. The system must be programmed prior to use in determining the location of the occupant. To program the system, a background image is taken for every combination of seat position and seat inclination available for a seat within the passenger compartment of the vehicle. The background images are stored in a memory. During the process of locating the occupant, the seat position and seat inclination are sensed and the background image for the particular combination of seat position and seat inclination is obtained from memory. An image of the passenger compartment of the vehicle is obtained and the background image associated with the particular combination of seat position and seat inclination is subtracted from the newly obtained image to remove background objects from the newly obtained image. The location of the occupant is then determined from the remaining portions of the image.